What is Yunis-Varon syndrome?
It is a rare genetic disease that affects multiple systems of the body. Its main symptoms affect the skeletal and nervous systems, as well as ectodermal tissue (hair and teeth). Since 1980 just 25 cases from 19 families have been diagnosed and recorded.
This syndrome is also known as:
Cleidocranial Dysplasia with Micrognathia, Absent Thumbs, and Distal Aphalangia
What gene changes cause Yunis-Varon syndrome?
Mutations in the FIG4 gene are responsible for the majority of the cases of the syndrome.
The syndrome has been reported in families where the parents of the children affected were related by blood. This increases the risk of them passing on a recessive disorder, as Yunis-Varon is.
What are the main symptoms of Yunis-Varon syndrome?
The unique facial features associated with the syndrome include a small head (microcephaly), a tented upper lip, small jaw, as well as sparse or absent eyebrows and eyelashes. Midface hypoplasia is also common with the syndrome, Midface hypoplasia is when the upper jaw, cheekbones and eye sockets have not grown with the rest of the face. This in turn creates a unique appearance.
Developmental delay and intellectual disability is also associated with the syndrome. These are often severe in nature.
Other severe symptoms of the syndrome include the absence or underdevelopment of the collarbones. This can lead to the development of ‘droopy’ shoulders in children affected by the syndrome. In infants the symptom usually leads to the delayed closing of the fontanels on their head.
Digit (finger and toe) abnormalities are also symptoms of the syndrome. This can include absent thumbs, as well as missing bones from the end of fingers and toes. Other bone abnormalities may be present which affect the digits. This often leads to shortened fingers and toes in affected individuals.
Other symptoms might include skeletal abnormalities, heart defects, and urinary tract abnormalities.
Possible clinical traits/features:
Broad secondary alveolar ridge, Cataract, Cardiomyopathy, Abnormal palate morphology, Abnormality of the neck, Abnormality of the sternum, Abnormality of the shoulder, Abnormality of the scapula, Aplastic/hypoplastic toenail, Anonychia, Aplastic clavicle, Aplasia/Hypoplasia of the distal phalanges of the toes, Aplasia/Hypoplasia of the earlobes, Aplasia/Hypoplasia of the distal phalanges of the hand, Aplasia/Hypoplasia of the corpus callosum, Aplasia/Hypoplasia of the cerebellum, Aplasia/Hypoplasia of the nipples, Aplasia/Hypoplasia of the nails, Aplasia/Hypoplasia of the middle phalanges of the hand, Aplasia/Hypoplasia of the iris, Aplasia/Hypoplasia of the hallux, Aplasia/Hypoplasia of the eyebrow, Arrhinencephaly, Adactyly, Absent thumb, Absent sternal ossification, Absent nipple, Blepharophimosis, Abnormality of the antihelix, Abnormal eyelash morphology, Abnormality of the hip bone, Abnormality of blood and blood-forming tissues, Abnormality of the clavicle, Abnormality of the fontanelles.
How is Yunis-Varon syndrome diagnosed?
To find out if someone has a diagnosis of Yunis-Varon syndrome, it is important to have a consultation and evaluation with a clinical genetic specialist. Specialists may also suggest specific genetic testing or other types of tests to help reach a diagnosis. FDNA’s AI technology can help speed up the diagnostic process by analyzing facial features and other health information.
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